PHOENIX, Ariz. — Michael Lee Hansen, the Phoenix man who admitted to trying to behead his mother, was sentenced to 8 1/2 years in prison on Thursday for attempted second-degree murder.

Hansen, 36, pleaded guilty in June to attacking his mother in a Phoenix restaurant on July 2, 2013, when police said he knocked his mother unconscious, stabbed her in the neck and attempted to cut off her head.

In court, Maricopa County Prosecutor Michelle Arino said the only reason her injuries were not more serious was because the knife Hansen grabbed at the Sakura Sushi and Steakhouse was a dull one the staff had quit using.

Arino described his mother as somewhat of a saint, saying she adopted Hansen and brought him to the United States so he could have a better life.

Arino also outlined Hansen's extensive history of drug use and said that his mother tried to get him help, but Hansen was unable to do so.

Hansen on Thursday stood quietly with his eyes fixated on the ground as Arino recounted the night he attacked his mother. He had been joking around with his attorney before sentencing; when the verdict was read, he struggled to hold back tears.

Hansen's defense attorney, John Taradash, focused more on Hansen's mental capacity and drug abuse as reasons for his attack. Taradash said Hansen was exhibiting symptoms of schizophrenia at the time of the attack.

"I could see it in his eyes when I first met him," he said.

Taradash said the attack could have easily been considered an aggravated assault because the mother did not suffer serious injuries, and asked the judge to sentence Hansen to seven years.

After Taradash's presentation, Hansen took his opportunity to address the court.